package com.taillive.commons;



import java.io.UnsupportedEncodingException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;

import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;


/**
 *  Des Encryption methods for bi-directional string encryption and decryption.
 *
 */
public class DesEncrypter {
    	
    	
    	private static DesEncrypter m_desEncrypter;
    	
    	private static DesEncrypter getDesEncrypter(){
    		if (m_desEncrypter==null)
    			m_desEncrypter	=new DesEncrypter("TAIL_A123");
    		return m_desEncrypter;
    	}
    	
    	private static DesEncrypter getDesEncrypter(String saltSource){
    		if (m_desEncrypter==null)
    			m_desEncrypter	=new DesEncrypter("TAIL_A123"+saltSource);
    		return m_desEncrypter;
    	}
    
    	public static String encryptString(String s){
    		return getDesEncrypter().encrypt(s);
    	}
    	public static String decryptString(String s){
    		return getDesEncrypter().decrypt(s);
    	}
    
    	public static String encryptString(String s,String saltSource){
    		return getDesEncrypter(saltSource).encrypt(s);
    	}
    	public static String decryptString(String s,String saltSource){
    		return getDesEncrypter(saltSource).decrypt(s);
    	}
    	
        Cipher ecipher;
        Cipher dcipher;
    
        // 8-byte Salt
        byte[] salt = {
            (byte)0xA9, (byte)0x9B, (byte)0xC8, (byte)0x32,
            (byte)0x56, (byte)0x35, (byte)0xE3, (byte)0x03
        };
    
        // Iteration count
        int iterationCount = 19;
    
        private DesEncrypter(String passPhrase) {
            try {
                // Create the key
                KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
                SecretKey key = SecretKeyFactory.getInstance(
                    "PBEWithMD5AndDES").generateSecret(keySpec);
                ecipher = Cipher.getInstance(key.getAlgorithm());
                dcipher = Cipher.getInstance(key.getAlgorithm());
    
                // Prepare the parameter to the ciphers
                AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);
    
                // Create the ciphers
                ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
                dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
            } catch (java.security.InvalidAlgorithmParameterException e) {
            } catch (java.security.spec.InvalidKeySpecException e) {
            } catch (javax.crypto.NoSuchPaddingException e) {
            } catch (java.security.NoSuchAlgorithmException e) {
            } catch (java.security.InvalidKeyException e) {
            }
        }
    
        public String encrypt(String str) {
            try {
                // Encode the string into bytes using utf-8
                byte[] utf8 = str.getBytes("UTF8");
    
                // Encrypt
                byte[] enc = ecipher.doFinal(utf8);
    
                // Encode bytes to base64 to get a string
                return new sun.misc.BASE64Encoder().encode(enc);
            } catch (javax.crypto.BadPaddingException e) {
            } catch (IllegalBlockSizeException e) {
            } catch (UnsupportedEncodingException e) {
            } catch (java.io.IOException e) {
            }
            return null;
        }
    
        public String decrypt(String str) {
            try {
                // Decode base64 to get bytes
                byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
    
                // Decrypt
                byte[] utf8 = dcipher.doFinal(dec);
    
                // Decode using utf-8
                return new String(utf8, "UTF8");
            } catch (javax.crypto.BadPaddingException e) {
            } catch (IllegalBlockSizeException e) {
            } catch (UnsupportedEncodingException e) {
            } catch (java.io.IOException e) {
            }
            return null;
        }


		public static void main(String args[]){
			
    		// Here is an example that uses the class
    		try {
        		// Encrypt
        		String encrypted = DesEncrypter.encryptString("Don't tell anybody!");
    
        		// Decrypt
        		String decrypted = DesEncrypter.decryptString(encrypted);
        		
        		System.out.println(encrypted);
        		System.out.println(decrypted);
        		
    		} catch (Exception e) {
    		}
    	
    	}


    }

